Organometallic compound, organic light-emitting device including the organometallic compound, and diagnostic compound including the organometallic compound

ABSTRACT

An organometallic compound represented by Formula 1:
 
M(L 11 ) n1 (L 12 ) n2   Formula 1
         wherein, in Formula 1, M is a third row transition metal, L 11  is a ligand represented by Formula 2, n1 is 1 or 2, and when n1 is two, two groups L 11  are identical to or different from each other, L 12  is an organic ligand, n2 is 0, 1, 2, or 3, and when n2 is two or more, two or more of groups L 12  are identical to or different from each other:       

     
       
         
         
             
             
         
       
         
         
           
             wherein, in Formula 2, groups and variables are the same as described in the specification.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Korean Patent Application No.10-2017-0038713, filed on Mar. 27, 2017 in the Korean IntellectualProperty Office, and all the benefits accruing therefrom under 35 U.S.C.§ 119, the content of which is incorporated herein in its entirety byreference.

BACKGROUND 1. Field

One or more embodiments relate to an organometallic compound, an organiclight-emitting device including the organometallic compound, and adiagnostic composition including the organometallic compound.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices, whichhave superior characteristics in terms of a viewing angle, a responsetime, a brightness, a driving voltage, and a response speed, and whichproduce full-color images.

In a typical example, an organic light-emitting device includes ananode, a cathode, and an organic layer disposed between the anode andthe cathode, wherein the organic layer includes an emission layer. Ahole transport region may be disposed between the anode and the emissionlayer, and an electron transport region may be disposed between theemission layer and the cathode. Holes provided from the anode may movetoward the emission layer through the hole transport region, andelectrons provided from the cathode may move toward the emission layerthrough the electron transport region. The holes and the electronsrecombine in the emission layer to produce excitons. These excitonstransit from an excited state to a ground state, thereby generatinglight.

Meanwhile, luminescent compounds may be used to monitor, sense, ordetect a variety of biological materials including cells and proteins.An example of the luminescent compounds includes a phosphorescentluminescent compound.

Various types of organic light emitting devices are known. However,there still remains a need in OLEDs having low driving voltage, highefficiency, high brightness, and long lifespan.

SUMMARY

Provided are an organometallic compound, an organic light-emittingdevice including the organometallic compound, and a diagnosticcomposition including the organometallic compound.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an aspect of an embodiment, provided is an organometalliccompound represented by Formula 1:

In Formulae 1 and 2,

M may be a third row transition metal,

L₁₁ may be a ligand represented by Formula 2,

n1 may be 1 or 2, and when n1 is two, two groups L₁₁ may be identical toor different from each other,

L₁₂ may be an organic ligand,

n2 may be 0, 1, 2, or 3, and when n2 is two or more, two or more ofgroups L₁₂ may be identical to or different from each other,

X₁ may be B(R₇), N(R₇), P(R₇), or As(R₇),

X₂ and X₃ may each be N or C,

CY₁ to CY₄ may each independently be selected from a C₅-C₃₀ carbocyclicgroup and a C₁-C₃₀ heterocyclic group,

T₁ and T₂ may each be selected from a single bond, a double bond,*—N[(L₅)_(b5)-(R₅)_(c5)]—*′, *—B(R₅)—*′, *—P(R₅)—*′, *—C(R₅)(R₆)—*′,*—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′, *—Se—*′, *—O—*′, *C(═O)*′,*—S(═O)—*′, *—S(═O)₂—*′, *—C(R₅)═*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′,*—C(═S)—*′, and *—C≡C—*′,

L₁ to L₅ may each independently be selected from a single bond, asubstituted or unsubstituted C₅-C₃₀ carbocyclic group, and a substitutedor unsubstituted C₁-C₃₀ heterocyclic group,

b1 to b5 may each independently be an integer of 1 to 5,

R₅ and R₆ may optionally be linked via a single bond or a first linkinggroup to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group ora substituted or unsubstituted C₁-C₃₀ heterocyclic group,

R₁ to R₇ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid group or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₇-C₆₀ arylalkylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substitutedor unsubstituted C₁-C₆₀ heteroarylthio group, a substituted orunsubstituted C₂-C₆₀ heteroarylalkyl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and—P(═O)(Q₈)(Q₉),

c1 to c5 may each independently be an integer of 1 to 5,

a1 to a4 may each independently be an integer of 0 to 20,

two of a plurality of neighboring groups R₁ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two of a plurality of neighboring groups R₂ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two of a plurality of neighboring groups R₃ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two of a plurality of neighboring groups R₄ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two or more of neighboring R₁ to R₄ may optionally be linked to form asubstituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group,

*, *′, and *″ in Formula 2 each independently indicate a binding site toM of Formula 1,

at least one substituent of the substituted C₅-C₃₀ carbocyclic group,the substituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₇-C₆₀ arylalkyl group, the substituted C₁-C₆₀heteroaryl group, the substituted C₁-C₆₀ heteroaryloxy group, thesubstituted C₁-C₆₀ heteroarylthio group, the substituted C₂-C₆₀heteroarylalkyl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substitute with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,—CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidino group,a hydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroarylgroup, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, aC₂-C₆₀ heteroarylalkyl group, a monovalent non-aromatic condensedpolycyclic group, a monovalent non-aromatic condensed heteropolycyclicgroup, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and—P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, aC₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Si(Q₂₃)(Q₂₄)(Q₂₅),—B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),and

Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independentlybe selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with atleast one selected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with at least oneselected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group,a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkylgroup, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group.

According to an aspect of an embodiment, provided is an organiclight-emitting device including:

a first electrode,

a second electrode, and

an organic layer disposed between the first electrode and the secondelectrode,

wherein the organic layer includes an emission layer and at least oneorganometallic compound as described above.

In the organic layer, the organometallic compound may serve as a dopant.

According to an aspect of an embodiment, provided is a diagnosticcomposition including at least one organometallic compound representedby Formula 1.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the FIGURE which is a schematic view of an organiclight-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

It will be understood that when an element is referred to as being “on”another element, it can be directly in contact with the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, orsection from another element, component, region, layer, or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this general inventive conceptbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure, and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

In an embodiment, an organometallic compound is provided. Theorganometallic compound according to an embodiment may be represented byFormula 1 below:M(L₁)_(n1)(L₁₂)_(n2).  Formula 1

M in Formula 1 may be a third row transition metal.

For example, M in Formula 1 may be Os, Pt, Pd, Au, Ru, Re, Rd, Rh, orIr, but embodiments of the present disclosure are not limited thereto.

In an embodiment, M in Formula 1 may be Os, Ru, Pt, or Pd, butembodiments of the present disclosure are not limited thereto.

The organometallic compound represented by Formula 1 may be a neutralcompound which is not composed of an ion pair of a cation and an anion.

In Formula 1, L₁₁ may be a ligand represented by Formula 2,

n1 may be 1 or 2, and when n1 is two, two groups L₁₁ may be identical toor different from each other,

L₁₂ may be an organic ligand, and

n2 may be 0, 1, 2, or 3, and when n2 is two or more, two or more ofgroups L₁₂ may be identical to or different from each other.

In an embodiment, in Formula 1, M may be Os, and n1 may be 1 or 2. Inone or more embodiments, in Formula 1, M may be Pt, n1 and n2 may eachbe 1, and L₁₂ may be a monodentate organic ligand, but embodiments ofthe present disclosure are not limited thereto.

In Formula 2, X₁ may be B(R₇), N(R₇), P(R₇), or As(R₇).

R₇ may not be not linked to M of Formula 1, and in addition, may not belinked to any of CY₁ to CY₄, T₁, and T₂ of Formula 2.

For example, X₁ may be P(R₇), but embodiments of the present disclosureare not limited thereto.

In Formula 2, X₂ and X₃ may each independently be N or C.

In Formulae 1 and 2, at least one selected from a bond between X₂ and Mand a bond between X₃ and M may be a covalent bond.

For example, in Formulae 1 and 2, one selected from a bond between X₂and M and a bond between X₃ and M may be a covalent bond, and the otherbond may be a covalent bond or a coordination bond.

For example, X₂ may be N and X₃ may be C; X₂ may be C and X₃ may be N;or X₂ and X₃ may be both N.

In Formula 2, CY₁ to CY₄ may each independently be selected from aC₅-C₃₀ carbocyclic group and a C₁-C₃₀ heterocyclic group.

For example, CY₁ to CY₄ may each independently be selected from abenzene group, a naphthalene group, an anthracene group, a phenanthrenegroup, a triphenylene group, a pyrene group, a chrysene group, acyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a pyrrolegroup, a thiophene group, a furan group, an indole group, an isoindolegroup, a benzoborole group, a benzophosphole group, an indene group, abenzosilole group, a benzogermole group, a benzothiophene group, abenzoselenophene group, a benzofuran group, a carbazole group, adibenzoborole group, a dibenzophosphole group, a fluorene group, adibenzosilole group, a dibenzogermole group, a dibenzothiophene group, adibenzoselenophene group, a dibenzofuran group, a dibenzothiophene5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxidegroup, an azacarbazole group, an azadibenzoborole group, anazadibenzophosphole group, an azafluorene group, an azadibenzosilolegroup, an azadibenzogermole group, an azadibenzothiophene group, anazadibenzoselenophene group, an azadibenzofuran group, anazadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, anazadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidinegroup, a pyrazine group, a pyridazine group, a triazine group, aquinoline group, an isoquinoline group, a quinoxaline group, aquinazoline group, a phenanthroline group, a pyrazole group, animidazole group, a triazole group, a tetrazole group, an oxazole group,an isooxazole group, a thiazole group, an isothiazole group, anoxadiazole group, a thiadiazole group, a benzopyrazole group, abenzimidazole group, a benzoxazole group, a benzothiazole group, abenzooxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup.

In Formula 2, T₁ and T₂ may each independently be selected from a singlebond, a double bond, *—N[(L₅)_(b5)-(R₅)_(c5)]—*′, *—B(R₅)—*′,*—P(R₅)—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′, *—Ge(R₅)(R₆)—*′, *—S—*′,*—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₅)═*′,*═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═S)—*′, and *—C≡C—*′.

L₁ to L₅ may each independently be selected from a single bond, asubstituted or unsubstituted C₅-C₃₀ carbocyclic group, and a substitutedor unsubstituted C₁-C₃₀ heterocyclic group.

For example, L₁ to L₅ may each independently be selected from:

a single bond, a benzene group, a naphthalene group, an anthracenegroup, a phenanthrene group, a triphenylene group, a pyrene group, achrysene group, a cyclopentadiene group, a furan group, a thiophenegroup, a silole group, an indene group, a fluorene group, an indolegroup, a carbazole group, a benzofuran group, a dibenzofuran group, abenzothiophene group, a dibenzothiophene group, a benzosilole group, adibenzosilole group, an azafluorene group, an azacarbazole group, anazadibenzofuran group, an azadibenzothiophene group, an azadibenzosilolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, a quinoline group, an isoquinolinegroup, a quinoxaline group, a quinazoline group, a phenanthroline group,a pyrrole group, a pyrazole group, an imidazole group, a triazole group,an oxazole group, an isooxazole group, a thiazole group, an isothiazolegroup, an oxadiazole group, a thiadiazole group, a benzopyrazole group,a benzimidazole group, a benzoxazole group, a benzothiazole group, abenzooxadiazole group and a benzothiadiazole group; and

a benzene group, a naphthalene group, an anthracene group, aphenanthrene group, a triphenylene group, a pyrene group, a chrysenegroup, a cyclopentadiene group, a furan group, a thiophene group, asilole group, an indene group, a fluorene group, an indole group, acarbazole group, a benzofuran group, a dibenzofuran group, abenzothiophene group, a dibenzothiophene group, a benzosilole group, adibenzosilole group, an azafluorene group, an azacarbazole group, anazadibenzofuran group, an azadibenzothiophene group, an azadibenzosilolegroup, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a triazine group, a quinoline group, an isoquinolinegroup, a quinoxaline group, a quinazoline group, a phenanthroline group,a pyrrole group, a pyrazole group, an imidazole group, a triazole group,an oxazole group, an isooxazole group, a thiazole group, an isothiazolegroup, an oxadiazole group, a thiadiazole group, a benzopyrazole group,a benzimidazole group, a benzoxazole group, a benzothiazole group, abenzooxadiazole group and a benzothiadiazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group,a triazinyl group, a fluorenyl group, a dimethylfluorenyl group, adiphenyfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group,a dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group,—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),

Q₃₁ to Q₃₉ may each independently be selected from:

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃,—CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CH₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group, each substituted with at least one selectedfrom deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.

For example, b1 to b5 each indicate the number of L₁ to L₅,respectively, and may each independently be an integer of 1 to 5. Whenb1 is two or more, two or more of groups L₁ may be identical to ordifferent from each other, when b2 is two or more, two or more of groupsL₂ may be identical to or different from each other, when b3 is two ormore, two or more of groups L₃ may be identical to or different fromeach other, when b4 is two or more, two or more of groups L₄ may beidentical to or different from each other, and when b5 is two or more,two or more of groups L₅ may be identical to or different from eachother.

For example, b1 to b5 may each independently be 1 or 2.

R₅ and R₆ may optionally be linked via a single bond or a first linkinggroup to form a substituted or unsubstituted C₅-C₃₀ carbocyclic group ora substituted or unsubstituted C₁-C₃₀ heterocyclic group (for example, a5-membered to 7-membered cyclic group having 5 or 6 carbons; a5-membered to 7-membered cyclic group having 5 or 6 carbons, eachsubstituted with at least one selected from deuterium, a cyano group,—F, a C₁-C₁₀ alkyl group, and a C₆-C₁₄ aryl group).

The first linking group may be selected from *—O—*′, *—S—*′,*—C(R₈)(R₉)—*′, *—C(R₈)═*′, *═C(R₈)—*′, *—C(R₈)═C(R₉)—*′, *—C(═O)—*′,*—C(═S)—*′, *—C≡C—*′, *—N(R₈)—*′, *—Si(R₈)(R₉)—*′, and *—P(R₈)(R₉)—*′,wherein R₈ and R₉ are each the same as described in connection with R₁of the present specification, and * and *′ each indicate a binding siteto a neighboring atom.

In an embodiment, T₁ and T₂ may each be a single bond, but embodimentsof the present disclosure are not limited thereto.

R₁ to R₇ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid group or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₇-C₆₀ arylalkylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substitutedor unsubstituted C₁-C₆₀ heteroarylthio group, a substituted orunsubstituted C₂-C₆₀ heteroarylalkyl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and—P(═O)(Q₈)(Q₉),

wherein Q₁ to Q₉ may each be independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with at least oneselected from a C₁-C₆₀ alkyl group and a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, aC₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group.

For example, R₁ to R₇ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,—SF₅, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkylgroup, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acycloctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a pyridinylgroup, and a pyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acycloctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, an imidazopyridinyl group, and an imidazopyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acycloctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, an imidazopyridinyl group, and an imidazopyrimidinyl group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,—CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cycloctyl group, an adamantanylgroup, a norbornanyl group, a norbornenyl group, a cyclopentenyl group,a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthylgroup, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a pyrrolyl group, a thiophenyl group, a furanyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group; and

—N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), and

Q₁ to Q₉ may each independently be selected from:

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃,—CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CH₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group, each substituted with at least one selectedfrom deuterium, a C₁-C₁₀ alkyl group, and a phenyl group.

In an embodiment, R₁ to R₇ may each independently be selected fromhydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃,—CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, groups represented by Formulae 9-1 to9-19, groups represented by Formulae 10-1 to 10-139, —N(Q₁)(Q₂),—Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉) (wherein Q₁ to Q₉ areeach independently the same as described above), but embodiments of thepresent disclosure are not limited thereto:

In Formulae 9-1 to 9-19 and 10-1 to 10-139, “Ph” indicates a phenylgroup, “TMS” indicates a trimethylsilyl group, “*” indicates a bindingsite to a neighboring atom.

In Formulae 9-1 to 9-19 and 10-1 to 10-139, c1 to c5 indicate the numberof R₁ to R₅, respectively, and may each independently be an integer of 1to 5. When c1 is two or more, two or more of groups R₁ may be identicalto or different from each other, when c2 is two or more, two or more ofgroups R₂ may be identical to or different from each other, when c3 istwo or more, two or more of groups R₃ may be identical to or differentfrom each other, when c4 is two or more, two or more of groups R₄ may beidentical to or different from each other, and when c5 is two or more,two or more of groups R₅ may be identical to or different from eachother. For example, c1 to c5 may each independently be 1, 2, or 3.

a1 to a4 indicate the number of *-(L₁)_(b1)-(R₁)_(c1),*-(L₂)_(b2)-(R₂)_(c2), *-(L₃)_(b3)-(R₃)_(c3), and *-(L₄)_(b4)-(R₄)_(c4),respectively, and may each independently be an integer of 0 to 20. Whena1 is two or more, two or more of groups *-(L₁)_(b1)-(R₁)_(c1) may beidentical to or different from each other, when a2 is two or more, twoor more of groups *-(L₂)_(b2)-(R₂)_(c2) may be identical to or differentfrom each other, when a3 is two or more, two or more of groups*-(L₃)_(b3)-(R₃)_(c3) may be identical to or different from each other,and when a4 is two or more, two or more of groups *-(L₄)_(b4)-(R₄)_(c4)may be identical to or different from each other. For example, a1 to a4may each independently be an integer of 1 to 5.

In Formula 1, two of a plurality of neighboring groups R₁ may optionallybe linked to form a substituted or unsubstituted C₅-C₃₀ carbocyclicgroup or a substituted or unsubstituted C₁-C₃₀ heterocyclic group, twoof a plurality of neighboring groups R₂ may optionally be linked to forma substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group, two of a plurality ofneighboring groups R₃ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, two of a plurality of neighboring groups R₄may optionally be linked to form a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, and two or more of neighboring R₁ to R₄ may optionally be linkedto form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group.

For example, in Formula 1, a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, each of which may be formed by two of a plurality of groups R₁,two of a plurality of groups R₂, two of a plurality of groups R₃, two ofa plurality of groups R₄, and two or more of neighboring R₁ to R₄ thatare optionally linked, may be selected from:

a pentadiene group, a cyclohexane group, a cycloheptane group, anadamantane group, a bicycle-heptane group, a bicycle-octane group, abenzene group, a pyridine group, a pyrimidine group, a pyrazine group, apyridazine group, a naphthalene group, an anthracene group, a tetracenegroup, a phenanthrene group, a dihydronaphthalene group, a phenalenegroup, a benzothiophene group, a benzofuran group, an indene group, anindole group, a benzosilole group, an azabenzothiophene group, anazabenzofuran group, an azaindene group, an azaindole group, and anazabenzosilole group;

a cyclohexane group, a cycloheptane group, an adamantane group, abicycle-heptane group, a bicycle-octane group, a benzene group, apyridine group, a pyrimidine group, a pyrazine group, a pyridazinegroup, a naphthalene group, an anthracene group, a tetracene group, aphenanthrene group, a dihydronaphthalene group, a phenalene group, abenzothiophene group, a benzofuran group, an indene group, an indolegroup, a benzosilole group, an azabenzothiophene group, an azabenzofurangroup, an azaindene group, an azaindole group, and an azabenzosilolegroup, each substituted with at least one R₁₁,

but embodiments of the present disclosure are not limited thereto.

R₁₁ is the same as described in connection with R₁.

In the present specification, “an azabenzothiophene group, anazabenzofuran group, an azaindene group, an azaindole group, anazabenzosilole group, an azadibenzothiophene group, an azadibenzofurangroup, an azafluorene group, an azacarbazole group, and anazadibenzosilole group” each independently indicate a heteroring havingthe same backbone as “a benzothiophene group, a benzofuran group, anindene group, an indole group, a benzosilole group, a dibenzothiophenegroup, a dibenzofuran group, a fluorene group, a carbazole group, and adibenzosilole group”, respectively, wherein at least one carbonconstituting the ring is substituted with nitrogen.

In an embodiment, a moiety represented by

in Formula 2 may be represented by one selected from Formulae CY1-1 toCY1-12:

In Formulae CY1-1 to CY1-12,

X₁, R₁, and R₂ are each independently the same as described above,

a14 may be an integer of 0 to 4,

a13 and a23 may each independently be an integer of 0 to 3,

a12 and a22 may each independently be an integer of 0 to 2,

* indicates a binding site to M of Formula 1, and

*′″ indicates a binding site to a neighboring atom.

In one or more embodiments, a moiety represented by

in Formula 2 may be represented by one selected from Formulae CY3-1 toCY3-9:

In Formulae CY3-1 to CY3-9,

X₂ and R₃ are the same as described above,

a35 may be an integer of 0 to 5,

a33 may be an integer of 0 to 3,

a32 may be an integer of 0 to 2,

*′ indicates a binding site to M of Formula 1, and

*′″ and

each indicate a binding site to a neighboring atom.

In one or more embodiments, a moiety represented by

in Formula 2 may be represented by one selected from Formulae CY4-1 toCY4-40:

In Formulae CY4-1 to CY4-40,

X₃ and R₄ are the same as described above,

X₄₁ may be O, S, N(R₄₁), or C(R₄₁)(R₄₂),

R₄₁ to R₄₈ are each independently the same as described in connectionwith R₄,

a46 may be an integer of 0 to 6,

a45 may be an integer of 0 to 5,

a44 may be an integer of 0 to 4,

a43 may be an integer of 0 to 3,

a42 may be an integer of 0 to 2,

*″ indicates a binding site to M of Formula 1, and

indicates a binding site to a neighboring atom.

In one or more embodiments,

the moiety represented by

in Formula 2 may be represented by Formula CY1 (1), and/or

the moiety represented by

in Formula 2 may be represented by one selected from Formulae CY3(1) toCY3(11), and/or

the moiety represented by

in Formula 2 may be represented by one selected from Formulae CY4(1) toCY4(23):

In Formulae CY1(1), CY3(1) to CY3(11), and CY4(1) to CY4(23), X₁ to X₃,R₃, and R₄ are each independently the same as described above, X₄₁ maybe O, S, N(R₄₁), or C(R₄₁)(R₄₂), and R_(4a) to R_(4d), R₄, and R₄₂ areeach independently the same described in connection with R₄, providedthat R₃, R₄, R_(4a) to R_(4d), R₄₁, and R₄₂ may not each independentlybe hydrogen, *, *′, and *″ each indicate a binding site to M of Formula1, and *′″ and

each indicate a binding site to a neighboring atom.

In Formula 1, L₁₂ may be selected from ligands represented by Formulae3A to 3D and 6-1:

In Formulae 3A to 3D,

Y₁₁ may be selected from O, N, N(Z₁), P(Z₁)(Z₂), and As(Z₁)(Z₂),

Y₁₂ may be selected from O, N, N(Z₃), P(Z₃)(Z₄), and As(Z₃)(Z₄),

T₁₁ may each independently be selected from a single bond, a doublebond, *—C(Z₁₁)(Z₁₂)—*′, *—C(Z₁₁)═C(Z₁₂)—*′, *═C(Z₁₁)—*′, *—C(Z₁₁)═*′,*═C(Z₁₁)—C(Z₁₂)═C(Z₁₃)—*′, C(Z₁₁)═C(Z₁₂)—C(Z₁₃)═*′, *—N(Z₁₁)—*′, and asubstituted or unsubstituted C₆-C₃₀ arylene group,

a11 may be an integer of 1 to 5,

Y₁₃ to Y₁₆ may each independently be C or N,

a bond between Y₁₃ and Y₁₄ may be a single bond or a double bond, and abond between Y₁₅ and Y₁₆ may be a single bond or a double bond,

CY₁₁ to CY₁₃ may each independently be selected from a C₅-C₃₀carbocyclic group, and a C₂-C₃₀ heterocyclic group,

Z₁ to Z₄ and Z₁₁ to Z₁₃ are each independently the same as described inconnection with R₁,

d1 and d2 may each independently be an integer of 0 to 10,

* and *′ each indicate a binding site to M of Formula 1, and

in Formula 6-1,

T₃ may be selected from a single bond, *—O—*′, *—S—*′, *—C(R₆₂)(R₆₃)—*′,*—C(R₆₂)═*′, *═C(R₆₂)—*′, *—C(R₆₂)═C(R₆₃)—*′, *—C(═O)—*′, *—C(═S)—*′,*—C≡C—*′, and *—N(R₆₂)—*′,

t3 may be an integer of 1 to 5,

R₆₁ to R₆₃ are each independently the same as described in connectionwith R₁, or may each independently be —P(Q₄₁)(Q₄₂)(Q₄₃),

Q₄₁ to Q₄₃ are each independently the same as described in connectionwith R₁, and

* indicates a binding site to M of Formula 1.

In an embodiment, L₁₂ in Formula 1 may be selected from a ligandrepresented by Formula 6-1, and T₃ in Formula 6-1 may not be a singlebond.

In one or more embodiments, L₁₂ in Formula 1 may be selected fromligands represented by Formulae 12-2 to 12-5:

In Formulae 12-1 to 12-5,

ring A₄ may be selected from a cyclopentane group, a cyclohexene group,a cycloheptene group, a benzene group, an indene group, a naphthalenegroup, an azulene group, a heptalene group, an indacene group, anacenaphthylene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentacene group, a hexacenegroup, a pentaphene group, a rubicene group, a coronene group, anovalene group, a pyrrole group, a thiophene group, a furan group, animidazole group, a pyrazole group, a thiazole group, an isothiazolegroup, an oxazole group, an isoxazole group, a pyridine group, apyrazine group, a pyrimidine group, a pyridazine group, an isoindolegroup, an indole group, an indazole group, a purine group, a quinolinegroup, an isoquinoline group, a benzoquinoline group, a quinoxalinegroup, a quinazoline group, a cinnoline group, a naphthyridine group, acarbazole group, a phenanthroline group, a benzimidazole group, abenzofuran group, a benzothiophene group, a benzothiazole group, anisobenzothiazole group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a thiadiazolegroup, a triazine group, a dibenzofuran group, a dibenzothiophene group,a benzocarbazole group, a dibenzocarbazole group, an imidazopyridinegroup, and an imidazopyrimidine group,

ring A₅ may be selected from a pyrrole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an isoindole group, an indolegroup, an indazole group, a purine group, a quinoline group, anisoquinoline group, a benzoquinoline group, a quinoxaline group, aquinazoline group, a cinnoline group, a naphthyridine group, a carbazolegroup, a phenanthroline group, a benzimidazole group, a benzofurangroup, a benzothiazole group, an isobenzothiazole group, a benzoxazolegroup, an isobenzoxazole group, a triazole group, a tetrazole group, anoxadiazole group, a thiadiazole group, a triazine group, abenzocarbazole group, a dibenzocarbazole group, an imidazopyridinegroup, and an imidazopyrimidine group,

ring A₆ may be selected from a furan group, an oxazole group, anisoxazole group, a benzofuran group, a benzoxazole group, anisobenzoxazole group, an oxadiazole group, and a dibenzofuran group,

ring A₇ may be selected from a thiophene group, a thiazole group, anisothiazole group, a benzothiophene group, a benzothiazole group, anisobenzothiazole group, a thiadiazole group, and a dibenzothiophenegroup,

Z₁ is the same as described in connection with R₁,

two or more of a plurality of groups Z₁ may optionally be linked to forma substituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₂-C₃₀ heterocyclic group,

e1 may be an integer of 0 to 8,

* indicates a binding site to M of Formula 1.

In one or more embodiments, L₁₂ in Formula 1 may be selected fromligands represented by Formulae 13-1 to 13-47 and 14-1 to 14-28, butembodiments of the present disclosure are not limited thereto:

In Formulae 13-1 to 13-47 and 14-1 to 14-28,

R₆₁ to R₆₃, Q₄₁ to Q₄₃, and Z₁ to Z₃ are each independently the same asdescribed in connection with R₁,

d2 may be an integer of 0 to 2,

d3 may be an integer of 0 to 3,

d4 may be an integer of 0 to 4,

d5 may be an integer of 0 to 5,

d6 may be an integer of 0 to 6,

d7 may be an integer of 0 to 7,

d8 may be an integer of 0 to 8, and

* indicates a binding site to M of Formula 1.

For example, the organometallic compound may be one selected fromCompounds 1 to 46, but embodiments of the present disclosure are notlimited thereto:

In Compounds 1 to 46, “^(t)Bu” indicates a tert-butyl group.

The ligand represented by Formula 2 may be a tridentate ligand having amoiety represented by

Therefore, in the ligand represented by Formula 2, Cyclometallated ring1 (refer to Formula 2′ below) formed by M, X₁, CY₂, T₁, and CY₃ may be aring including at least 6-membered ring (for example, a 6-membered ring,a 7-membered ring, or a 8-membered ring):

In this regard, the organometallic compound including the ligandrepresented by Formula 2 may have relatively short radiative decay timeand strong metal-ligand charge transfer. In addition, the organometalliccompound including the ligand represented by Formula 2 may haveexcellent chemical resistance, electrical stability, and robustness, atthe same time. Furthermore, due to the presence of Cyclometallated ring1 which is at least 6-membered ring, a stable binding angle between M(metal) and L₁₁ (tridentate ligand represented by Formula 2) in Formula1 may be formed, and thus, the molecular stability of the organometalliccompound represented by Formula 1 may be improved. Therefore, anelectronic device, for example, an organic light-emitting device,including the organometallic compound, may have improved emissionefficiency.

For example, regarding Compounds 1 to 46, the highest occupied molecularorbital (HOMO) levels, the lowest unoccupied molecular orbital (LUMO)levels, and triplet (T₁) energy levels are measured according to thedensity functional theory (DFT) of the Gaussian program (structurallyoptimized at a level of B3LYP, 6-31G(d,p)), and the measurement resultsare shown in Table 1.

TABLE 1 T1 energy Compound No. HOMO (eV) LUMO (eV) level (eV) 1 −4.441−1.229 2.285 2 −4.421 −1.428 2.155 3 −4.420 −1.324 2.234 4 −4.410 −1.5122.084 5 −4.612 −1.394 2.398 6 −4.579 −1.529 2.272 7 −5.069 −1.691 2.5198 −5.010 −1.783 2.416 9 −4.338 −1.336 2.227 10 −4.315 −1.482 2.091 11−4.469 −1.422 2.205 12 −4.453 −1.594 2.089 13 −4.413 −1.584 2.008 14−4.339 −1.494 2.060 15 −4.329 −1.589 1.947 16 −4.259 −1.602 1.820 17−4.397 −1.514 2.091 18 −4.378 −1.599 1.974 19 −4.307 −1.612 1.847 20−4.732 −1.640 2.174 21 −4.449 −1.573 2.053 22 −4.801 −1.783 2.124 23−4.649 −1.634 2.074 24 −4.276 −1.550 1.876 25 −4.726 −1.772 2.033 26−4.706 −1.553 2.216 27 −4.462 −1.454 2.180 28 −4.760 −1.693 2.162 29−4.620 −1.539 2.113 30 −4.407 −1.446 2.080 31 −4.667 −1.685 2.065 32−4.971 −1.752 2.407 33 −4.968 −1.758 2.400 34 −4.982 −1.651 2.498 35−4.881 −1.602 2.423 36 −5.324 −1.913 2.521 37 −5.212 −2.041 2.348 38−5.153 −1.990 2.342 39 −5.141 −1.991 2.330 40 −4.878 −1.913 2.101 41−5.274 −2.219 2.205 42 −5.201 −2.126 2.220 43 −5.172 −2.210 2.103 44−5.146 −2.174 2.096 45 −5.120 −2.133 2.129 46 −5.092 −2.100 2.109

From Table 1, it has been confirmed that the organometallic compoundrepresented by Formula 1 has such electric characteristics that aresuitable for use in an electric device, for example, for use as a dopantfor an organic light-emitting device.

Synthesis methods of the organometallic compound represented by Formula1 may be understood by one of ordinary skill in the art by referring toSynthesis Examples provided below.

The organometallic compound represented by Formula 1 may be suitable foruse in an organic layer of an organic light-emitting device, forexample, for use as a dopant in an emission layer of the organic layer.Thus, according to another aspect of an embodiment, provided is anorganic light-emitting device including: a first electrode, a secondelectrode, and an organic layer that is disposed between the firstelectrode and the second electrode, wherein the organic layer includesan organic layer including an emission layer and at least oneorganometallic compound represented by Formula 1.

The organic light-emitting device may have, due to the inclusion of anorganic layer including the organometallic compound represented byFormula 1, a low driving voltage, high efficiency, high power, highquantum efficiency, a long lifespan, a low roll-off ratio, and excellentcolor purity.

The organometallic compound represented by Formula 1 may be used betweena pair of electrodes of the organic light-emitting device. For example,the organometallic compound represented by Formula 1 may be included inthe emission layer. In this regard, the organometallic compound may actas a dopant, and the emission layer may further include a host (that is,an amount of the organometallic compound represented by Formula 1 issmaller than an amount of the host).

The expression “(an organic layer) includes at least one oforganometallic compounds” as used herein may include an embodiment inwhich “(an organic layer) includes identical organometallic compoundsrepresented by Formula 1” and an embodiment in which “(an organic layer)includes two or more different organometallic compounds represented byFormula 1.”

For example, the organic layer may include, as the organometalliccompound, only Compound 1. In this regard, Compound 1 may be included inan emission layer of the organic light-emitting device. In one or moreembodiments, the organic layer may include, as the organometalliccompound, Compound 1 and Compound 2. In this regard, Compound 1 andCompound 2 may be included in an identical layer (for example, Compound1 and Compound 2 both may be included in an emission layer).

The first electrode may be an anode, which is a hole injectionelectrode, and the second electrode may be a cathode, which is anelectron injection electrode; or the first electrode may be a cathode,which is an electron injection electrode, and the second electrode maybe an anode, which is a hole injection electrode.

In an embodiment, in the organic light-emitting device, the firstelectrode is an anode, and the second electrode is a cathode, and theorganic layer further includes a hole transport region disposed betweenthe first electrode and the emission layer and an electron transportregion disposed between the emission layer and the second electrode,wherein the hole transport region includes a hole injection layer, ahole transport layer, an electron blocking layer, a buffer layer, or anycombination thereof, and wherein the electron transport region includesa hole blocking layer, an electron transport layer, an electroninjection layer, or any combination thereof.

The term “organic layer” as used herein refers to a single layer and/ora plurality of layers between the first electrode and the secondelectrode of the organic light-emitting device. The “organic layer” mayinclude, in addition to an organic compound, an organometallic complexincluding metal.

The FIGURE is a schematic view of an organic light-emitting device 10according to an embodiment. Hereinafter, the structure of an organiclight-emitting device according to an embodiment and a method ofmanufacturing an organic light-emitting device according to anembodiment will be described in connection with the FIGURE. The organiclight-emitting device 10 includes a first electrode 11, an organic layer15, and a second electrode 19, which are sequentially stacked.

A substrate may be additionally disposed under the first electrode 11 orabove the second electrode 19. For use as the substrate, any substratethat is used in general organic light-emitting devices may be used, andthe substrate may be a glass substrate or a transparent plasticsubstrate, each having excellent mechanical strength, thermal stability,transparency, surface smoothness, ease of handling, and waterresistance.

The first electrode 11 may be formed by depositing or sputtering amaterial for forming the first electrode 11 on the substrate. The firstelectrode 11 may be an anode. The material for forming the firstelectrode 11 may be selected from materials with a high work function tofacilitate hole injection. The first electrode 11 may be a reflectiveelectrode, a semi-transmissive electrode, or a transmissive electrode.The material for forming the first electrode may be, for example, indiumtin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zincoxide (ZnO). In one or more embodiments, magnesium (Mg), aluminum (Al),aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), ormagnesium-silver (Mg—Ag) may be used as the material for forming thefirst electrode.

The first electrode 11 may have a single-layered structure or amulti-layered structure including two or more layers. For example, thefirst electrode 11 may have a three-layered structure of ITO/Ag/ITO, butthe structure of the first electrode 110 is not limited thereto.

The organic layer 15 is disposed on the first electrode 11.

The organic layer 15 may include a hole transport region, an emissionlayer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11and the emission layer.

The hole transport region may include a hole injection layer, a holetransport layer, an electron blocking layer, a buffer layer, or anycombination thereof.

The hole transport region may include only either a hole injection layeror a hole transport layer. In one or more embodiments, the holetransport region may have a hole injection layer/hole transport layerstructure or a hole injection layer/hole transport layer/electronblocking layer structure, which are sequentially stacked in this statedorder from the first electrode 11.

A hole injection layer may be formed on the first electrode 11 by usingone or more suitable methods selected from vacuum deposition, spincoating, casting, or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, thedeposition conditions may vary according to a compound that is used toform the hole injection layer, and the structure and thermalcharacteristics of the hole injection layer. For example, the depositionconditions may include a deposition temperature of about 100 to about500° C., a vacuum pressure of about 10⁻⁸ to about 10⁻³ torr, and adeposition rate of about 0.01 Angstroms per second (A/sec) to about 100Å/sec. However, the deposition conditions are not limited thereto.

When the hole injection layer is formed using spin coating, coatingconditions may vary according to the material used to form the holeinjection layer, and the structure and thermal properties of the holeinjection layer. For example, a coating speed may be from about 2,000revolutions per minute (rpm) to about 5,000 rpm, and a temperature atwhich a heat treatment is performed to remove a solvent after coatingmay be from about 80° C. to about 200° C. However, the coatingconditions are not limited thereto.

Conditions for forming a hole transport layer and an electron blockinglayer may be understood by referring to conditions for forming the holeinjection layer.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB, R-NPB, TPD, Spiro-TPD, Spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201 below, anda compound represented by Formula 202 below:

Ar₁₀₁ and Ar₁₀₂ in Formula 201 may each be selected from:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, and a pentacenylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anacenaphthylene group, a fluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, and a pentacenylene group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroarylgroup, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, aC₂-C₆₀ heteroarylalkyl group, a monovalent non-aromatic condensedpolycyclic group, and a monovalent non-aromatic condensedheteropolycyclic group.

In Formula 201, xa and xb may each independently be an integer from 0 to5, or 0, 1, or 2. For example, xa is 1 and xb is 0, but xa and xb arenot limited thereto.

R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to R₁₂₄ in Formulae 201 and 202 mayeach independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₁₀ alkyl group (for example, a methyl group, an ethyl group, apropyl group, a butyl group, a pentyl group, a hexyl group, and so on),or a C₁-C₁₀ alkoxy group (for example, a methoxy group, an ethoxy group,a propoxy group, a butoxy group, a pentoxy group, and so on);

a C₁-C₁₀ alkyl group or a C₁-C₁₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, and a phosphoric acidgroup or a salt thereof;

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, and a pyrenyl group; and

a phenyl group, a naphthyl group, an anthracenyl group, a fluorenylgroup, and a pyrenyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₁₀ alkyl group, and a C₁-C₁₀ alkoxy group, but embodiments of thepresent disclosure are not limited thereto.

R₁₀₉ in Formula 201 may be selected from:

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinylgroup; and

a phenyl group, a naphthyl group, an anthracenyl group, and a pyridinylgroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, ananthracenyl group, and a pyridinyl group.

According to an embodiment, the compound represented by Formula 201 maybe represented by Formula 201A, but embodiments of the presentdisclosure are not limited thereto:

R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ in Formula 201A are each independently thesame as described above.

For example, the compound represented by Formula 201 and the compoundrepresented by Formula 202 may each include Compounds HT1 to HT20 below,but embodiments of the present disclosure are not limited thereto:

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When thehole transport region includes at least one of a hole injection layerand a hole transport layer, the thickness of the hole injection layermay be in a range of about 100 Å to about 10,000 Å, and for example,about 100 Å to about 1,000 Å, and the thickness of the hole transportlayer may be in a range of about 50 Å to about 2,000 Å, and for example,about 100 Å to about 1,500 Å. While not wishing to be bound by theory,it is understood that when the thicknesses of the hole transport region,the hole injection layer, and the hole transport layer are within theseranges, satisfactory hole transporting characteristics may be obtainedwithout a substantial increase in driving voltage.

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant. Thep-dopant may be one selected from a quinone derivative, a metal oxide,and a cyano group-containing compound, but embodiments of the presentdisclosure are not limited thereto. Non-limiting examples of thep-dopant are a quinone derivative, such as tetracyanoquinonedimethane(TCNQ) or 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane(F4-TCNQ); a metal oxide, such as a tungsten oxide or a molybdeniumoxide; and a cyano group-containing compound, such as Compound HT-D1below, but are not limited thereto.

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distanceaccording to a wavelength of light emitted from the emission layer, andthus, efficiency of a formed organic light-emitting device may beimproved.

Then, an emission layer may be formed on the hole transport region byvacuum deposition, spin coating, casting, LB deposition, or the like.When the emission layer is formed by vacuum deposition or spin coating,the deposition or coating conditions may be similar to those applied informing the hole injection layer although the deposition or coatingconditions may vary according to a compound that is used to form theemission layer.

Meanwhile, when the hole transport region includes an electron blockinglayer, a material for the electron blocking layer may be selected frommaterials for the hole transport region described above and materialsfor a host to be explained later. However, the material for the electronblocking layer is not limited thereto. For example, when the holetransport region includes an electron blocking layer, a material for theelectron blocking layer may be mCP, which will be explained later.

The emission layer may include a host and a dopant, and the dopant mayinclude the organometallic compound represented by Formula 1 or thecomposition containing the organometallic compound represented byFormula 1.

The host may include at least one selected from TPBi, TBADN, ADN (alsoreferred to as “DNA”), CBP, CDBP, TCP, mCP, Compound H50, Compound H51,and Compound H52:

In one or more embodiments, the host may further include a compoundrepresented by Formula 301 below.

Ar₁₁₁ and Ar₁₁₂ in Formula 301 may each independently be selected from:

a phenylene group, a naphthylene group, a phenanthrenylene group, and apyrenylene group; and

a phenylene group, a naphthylene group, a phenanthrenylene group, and apyrenylene group, each substituted with at least one selected from aphenyl group, a naphthyl group, and an anthracenyl group.

Ar₁₁₃ to Ar₁₁₆ in Formula 301 may each independently be selected from:

a C₁-C₁₀ alkyl group, a phenyl group, a naphthyl group, a phenanthrenylgroup, and a pyrenyl group; and

a phenyl group, a naphthyl group, a phenanthrenyl group, and a pyrenylgroup, each substituted with at least one selected from a phenyl group,a naphthyl group, and an anthracenyl group.

g, h, i, and j In Formula 301 may each independently be an integer from0 to 4, and may be, for example, 0, 1, or 2.

Ar₁₁₃ to Ar₁₁₆ in Formula 301 may each be selected from:

a C₁-C₁₀ alkyl group substituted with at least one selected from aphenyl group, a naphthyl group, and an anthracenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl, aphenanthrenyl group, and a fluorenyl group;

a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group,a phenanthrenyl group, and a fluorenyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthylgroup, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, anda fluorenyl group; and

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the host may include a compound representedby Formula 302 below:

Ar₁₂₂ to Ar₁₂₅ in Formula 302 are the same as described in detail inconnection with Ar₁₁₃ in Formula 301.

Ar₁₂₆ and Ar₁₂₇ in Formula 302 may each be a C₁-C₁₀ alkyl group (forexample, a methyl group, an ethyl group, or a propyl group).

k and l in Formula 302 may each independently be an integer from 0 to 4.For example, k and l may be 0, 1, or 2.

The compound represented by Formula 301 and the compound represented byFormula 302 may include Compounds H1 to H42 below, but are not limitedthereto:

When the organic light-emitting device is a full-color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, and a blue emission layer. Inone or more embodiments, due to a stacked structure including a redemission layer, a green emission layer, and/or a blue emission layer,the emission layer may emit white light.

When the emission layer includes a host and a dopant, an amount of thedopant may be in a range of about 0.01 parts to about 15 parts by weightbased on 100 parts by weight of the host, but embodiments of the presentdisclosure are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å toabout 1,000 Å, for example, about 200 Å to about 600 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the emission layer is within this range, excellent light-emissioncharacteristics may be obtained without a substantial increase indriving voltage.

Then, an electron transport region may be disposed on the emissionlayer.

The electron transport region may include a hole blocking layer, anelectron transport layer, an electron injection layer, or anycombination thereof.

For example, the electron transport region may have a hole blockinglayer/electron transport layer/electron injection layer structure or anelectron transport layer/electron injection layer structure, but thestructure of the electron transport region is not limited thereto. Theelectron transport layer may have a single-layered structure or amulti-layered structure including two or more different materials.

Conditions for forming the hole blocking layer, the electron transportlayer, and the electron injection layer which constitute the electrontransport region may be understood by referring to the conditions forforming the hole injection layer.

When the electron transport region includes a hole blocking layer, thehole blocking layer may include, for example, at least one of BCP,Bphen, and BAlq but embodiments of the present disclosure are notlimited thereto:

A thickness of the hole blocking layer may be in a range of about 20 Åto about 1,000 Å, for example, about 30 Å to about 300 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the hole blocking layer is within these ranges, the hole blockinglayer may have improved hole blocking ability without a substantialincrease in driving voltage.

The electron transport layer may include at least one selected from BCP,Bphen, Alq₃, BAlq, TAZ, and NTAZ:

In one or more embodiments, the electron transport layer may include atleast one of ET1 to ET25, but are not limited thereto:

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whilenot wishing to be bound by theory, it is understood that when thethickness of the electron transport layer is within the range describedabove, the electron transport layer may have satisfactory electrontransport characteristics without a substantial increase in drivingvoltage.

Also, the electron transport layer may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include a Li complex. The Li complexmay include, for example, Compound ET-D1 (lithium 8-hydroxyquinolate,LiQ) or ET-D2.

The electron transport region may include an electron injection layerthat promotes flow of electrons from the second electrode 19 thereinto.

The electron injection layer may include at least one selected from LiF,NaCl, CsF, Li₂O, and BaO.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the electron injection layer is within the range described above, theelectron injection layer may have satisfactory electron injectioncharacteristics without a substantial increase in driving voltage.

The second electrode 19 is disposed on the organic layer 15. The secondelectrode 19 may be a cathode. A material for forming the secondelectrode 19 may be selected from metal, an alloy, an electricallyconductive compound, and a combination thereof, which have a relativelylow work function. For example, lithium (Li), magnesium (Mg), aluminum(Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In),or magnesium-silver (Mg—Ag) may be used as a material for forming thesecond electrode 19. In one or more embodiments, to manufacture atop-emission type light-emitting device, a transmissive electrode formedusing ITO or IZO may be used as the second electrode 19.

Hereinbefore, the organic light-emitting device has been described withreference to the FIGURE, but embodiments of the present disclosure arenot limited thereto.

According to another aspect of an embodiment, provided is a diagnosticcomposition including at least one organometallic compound representedby Formula 1.

The organometallic compound represented by Formula 1 provides highluminescent efficiency. Accordingly, a diagnostic composition includingthe organometallic compound may have high diagnostic efficiency.

The diagnostic composition may be used in various applications includinga diagnosis kit, a diagnosis reagent, a biosensor, and a biomarker.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched saturated aliphatic hydrocarbon monovalent group having 1 to 60carbon atoms, and non-limiting examples thereof include a methyl group,an ethyl group, a propyl group, an iso-butyl group, a sec-butyl group, atert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and non-limiting examples thereof include a methoxy group, an ethoxygroup, and an iso-propyloxy group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup formed by including at least one carbon-carbon double bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethenyl group, a propenyl group, and a butenyl group.The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalentgroup having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup formed by including at least one carbon-carbon triple bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andnon-limiting examples thereof include a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.The term “C₃-C₁₀ cycloalkylene group” as used herein refers to adivalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent saturated monocyclic group having at least one heteroatomselected from N, O, P, Si and S as a ring-forming atom and 1 to 10carbon atoms, and non-limiting examples thereof include atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic hydrocarbon group that has 3 to 10 carbon atomsand at least one carbon-carbon double bond in the ring thereof and noaromaticity, and non-limiting examples thereof include a cyclopentenylgroup, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group” as used herein refers to a divalent group havingthe same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, P, Si, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one double bond in its ring. Examples of the C₁-C₁₀heterocycloalkenyl group are a 2,3-dihydrofuranyl group and a2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, anaphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenylgroup, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused toeach other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system that has at least oneheteroatom selected from N, O, P, Si, and S as a ring-forming atom, and1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as usedherein refers to a divalent group having a heterocyclic aromatic systemthat has at least one heteroatom selected from N, O, P, Si and S as aring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples ofthe C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinylgroup, a pyrazinyl group, a pyridazinyl group, a triazinyl group, aquinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroarylgroup and the C₁-C₆₀ heteroarylene group each include two or more rings,the rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group” as used herein indicates —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), the term “C₆-C₆₀ arylthio group” as usedherein indicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group), and theterm “C₇-C₆₀ arylalkyl group” as used herein indicates -A₁₀₄A₁₀₅(wherein A₁₀₄ is the C₆-C₅₉ aryl group and A₁₀₅ is the C₁-C₅₃ alkylenegroup).

The term “C₁-C₆₀ heteroaryloxy group” as used herein refers to —OA₁₀₆(wherein A₁₀₆ is the C₁-C₆₀ heteroaryl group), and the term “C₁-C₆₀heteroarylthio group” as used herein indicates —SA₁₀₇ (wherein A₁₀₇ isthe C₁-C₆₀ heteroaryl group).

The term “C₂-C₆₀ heteroarylalkyl group” as used herein refers to-A₁₀₈A₁₀₉ (A₁₀₉ is a C₁-C₅₉ heteroaryl group, and A₁₀₈ is a C₁-C₅₈alkylene group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed to each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. Examples of the monovalent non-aromatic condensed polycyclicgroup include a fluorenyl group. The term “divalent non-aromaticcondensed polycyclic group” as used herein refers to a divalent grouphaving the same structure as the monovalent non-aromatic condensedpolycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 2 to 60carbon atoms) having two or more rings condensed to each other, aheteroatom selected from N, O, P, Si, and S, other than carbon atoms, asa ring-forming atom, and no aromaticity in its entire molecularstructure. Non-limiting examples of the monovalent non-aromaticcondensed heteropolycyclic group include a carbazolyl group. The term“divalent non-aromatic condensed heteropolycyclic group” as used hereinrefers to a divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₅-C₃₀ carbocyclic group” as used herein refers to a saturatedor unsaturated cyclic group having, as a ring-forming atom, 5 to 30carbon atoms only. The C₅-C₃₀ carbocyclic group may be a monocyclicgroup or a polycyclic group.

The term “C₁-C₃₀ heterocyclic group” as used herein refers to asaturated or unsaturated cyclic group having, as a ring-forming atom, atleast one heteroatom selected from N, O, Si, P, Si and S other than 1 to30 carbon atoms. The C₁-C₃₀ heterocyclic group may be a monocyclic groupor a polycyclic group.

At least one substituent of the substituted C₅-C₃₀ carbocyclic group,the substituted C₂-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₇-C₆₀ arylalkyl group, the substituted C₁-C₆₀heteroaryl group, the substituted C₁-C₆₀ heteroaryloxy group, thesubstituted C₁-C₆₀ heteroarylthio group, the substituted C₂-C₆₀heteroarylalkyl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenylgroup, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,—CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid group or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroarylgroup, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, aC₂-C₆₀ heteroarylalkyl group, a monovalent non-aromatic condensedpolycyclic group, a monovalent non-aromatic condensed heteropolycyclicgroup, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and—P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxygroup, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, aC₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂),—Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),and

Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with at least oneselected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group,a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryl group substituted with at least one selected fromdeuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, aC₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group.

Hereinafter, a compound and an organic light-emitting device accordingto embodiments are described in detail with reference to SynthesisExample and Examples. However, the organic light-emitting device is notlimited thereto. The wording “B was used instead of A” used indescribing Synthesis Examples means that an amount of A used wasidentical to an amount of B used, in terms of a molar equivalent.

EXAMPLES Synthesis Example 1: Synthesis of Compound 1

Synthesis of Intermediate A5

2-(Pinacolboronate phenyl)pyridine (2.59 grams (g), 9.23 millimoles(mmol)), 2,6-dibromoaniline (2.32 g, 9.23 mmol), Pd(PPh₃)₄ (0.75 g, 0.65mmol), K₂CO₃ (1.91 g, 13.8 mmol) were mixed with 30 milliliters (mL) oftetrahydrofuran and 15 mL of distilled water. The mixed solution wasstirred at a temperature of 75° C. for 5 hours, and then, cooled to roomtemperature. The reaction mixture was extracted by using ethyl acetate.The organic layer was dried over anhydrous magnesium sulfate (MgSO₄) toremove water and subsequently filtered under reduced pressure, and thenevaporated under reduced pressed to remove the ethyl acetate. Theresidue obtained therefrom was then separated and purified by columnchromatography with ethyl acetate:hexane=1:15 as an eluent, therebyobtaining 2.30 g (77%) of Intermediate A5. The obtained compound wasconfirmed by LCMS and 1H NMR.

¹H-NMR (CDCl₃) δ 8.61 (d, 1H), 8.30 (d, 1H), 8.22 (s, 1H), 7.53 (m, 5H),7.20 (d, 1H), 7.05 (m, 1H), 6.81 (m, 1H), 5.70 (br. s, 2H)

MS: m/z 325.04 [(M+1)⁺]

Synthesis of Intermediate A4

Intermediate A5 (2.30 g, 7.08 mmol), 2-bromophenylboronic acid (1.42 g,7.08 mmol), Pd(PPh₃)₄ (0.57 g, 0.50 mmol), and K₂CO₃ (1.47 g, 10.6 mmol)were mixed with 15 mL of toluene (PhMe), 10 mL of distilled water, and 5mL of ethanol. The mixed solution was stirred at a temperature of 95° C.for 6 hours, and then, cooled to room temperature. The reaction mixturewas extracted by using ethyl acetate. The organic layer was dried overMgSO₄ to remove water and subsequently filtered under reduced pressure,and then evaporated under reduced pressed to remove the ethyl acetate.The residue obtained therefrom was then separated and purified by columnchromatography with ethyl acetate:hexane=1:15 as an eluent, therebyobtaining 2.21 g (78%) of Intermediate A4. The obtained compound wasconfirmed by LCMS and 1H NMR.

¹H-NMR (CDCl₃) δ 8.56 (d, 1H), 8.31 (d, 1H), 8.23 (s, 1H), 7.54 (m, 8H),7.30 (m, 2H), 6.99 (m, 2H), 5.71 (br. s, 2H)

MS: m/z 401.05 [(M+1)⁺]

Synthesis of Intermediate A3

Intermediate A4 (2.21 g, 5.51 mmol) was dissolved in 60 mL of aceticacid at a temperature of 0° C., and NaNO₂ (1.14 g, 16.5 mmol) dissolvedin 1.1 mL of sulfuric acid was added thereto. The mixed solution wasstirred at room temperature for 1 hour. CuBr (2.37 g, 16.5 mmol)dissolved in 47% HBr aqueous solution (45 mL) was then slowly added tothe resulting mixed solution, and the reaction mixture was stirred at atemperature of 80° C. for 1 and half hours. The resultant obtainedtherefrom was cooled to room temperature. The reaction mixture wasextracted by using ethyl acetate. The organic layer was neutralized with1 M NaOH aqueous solution, dried by using MgSO₄ to remove water, andfiltered under reduced pressure, and then evaporated under reducedpressed to remove the ethyl acetate. The residue obtained therefrom wasthen separated and purified by column chromatography with ethylacetate:hexane=1:25 as an eluent, thereby obtaining 1.77 g (69%) ofIntermediate A3. The obtained compound was confirmed by LCMS and 1H NMR.

¹H-NMR (CDCl₃) δ 8.56 (d, 1H), 8.32 (d, 1H), 8.22 (s, 1H), 7.55 (m, 9H),7.28 (m, 2H), 7.01 (m, 1H)

MS: m/z 463.98 [(M+1)⁺]

Synthesis of Intermediate A2

Intermediate A3 (1.77 g, 3.81 mmol) was dissolved in 60 mL oftetrahydrofuran at a temperature of −78° C., and then, n-BuLi (7.62mmol) dissolved in n-hexane was added thereto. The mixed solution wasstirred at a temperature of −78° C. for 1 hour. PCl₃ (2.37 g, 3.81 mmol)was slowly added thereto, and the reaction mixture was stirred at roomtemperature for 1 hour. After the completion of the reaction wasconfirmed, the reaction mixture was heated for 1 hour, and the resultingsolution was cooled to room temperature, thereby obtaining a 0.65 g(46%) of a solid product, Intermediate A2. The obtained compound wasused for the next reaction without being subjected to additionalpurification.

Synthesis of Intermediate A1

Intermediate A2 (0.65 g, 1.75 mmol) was dissolved in 20 mL oftetrahydrofuran at a temperature of 0° C., and CH₃MgBr (1.75 mmol) wasslowly added thereto at room temperature, followed by being stirred for3 hours at room temperature. The reaction mixture was extracted by usingethyl acetate. The organic layer was dried over MgSO₄ to remove waterand subsequently filtered under reduced pressure, and then evaporatedunder reduced pressed to remove the ethyl acetate. The residue obtainedtherefrom was then separated and purified by column chromatography withethyl acetate:hexane 1:25 as an eluent, thereby obtaining 0.50 g (82%)of Intermediate A1. The obtained compound was confirmed by LCMS and 1HNMR.

¹H-NMR (CDCl₃) δ 8.57 (d, 1H), 8.05 (s, 1H), 7.98 (d, 1H), 7.70 (m, 2H),7.66 (d, 1H), 7.51 (t, 1H), 7.42 (m, 1H), 7.31 (m, 4H), 7.20 (m, 2H),7.09 (d, 1H), 2.01 (s, 3H)

MS: m/z 352.11 [(M+1)⁺]

Synthesis of Compound 1

Intermediate A1 (0.50 g, 1.42 mmol) and OsH₄(PPh₃)₃ (0.61 g, 0.62 mmol)were added to 5 mL of decahydronaphthalene, and the mixed solution wasallowed to react at a temperature of 200° C. for 2 hours. The resultingsolution was cooled to room temperature and filtered under reducedpressure. The filtered residue was separated and purified by columnchromatography with ethyl acetate:hexane=1:10 as an eluent, therebyobtaining 0.45 g (82%) of Compound 1. The obtained compound wasconfirmed by LCMS and 1H NMR.

¹H-NMR (CDCl₃) δ 8.60 (d, 2H), 8.31 (d, 2H), 7.99 (d, 2H), 7.75 (m, 8H),7.56 (m, 12H), 7.02 (m, 2H), 1.99 (s, 6H)

MS: m/z 893.16 [(M+1)⁺]

Synthesis Example 2: Synthesis of Compound 7

Synthesis of Intermediate B6

2-bromo-6-(1-(tetrahydro-2H-pyran-2-yl)-3-(trifluoromethyl)-1H-pyrazol-5-yl)pyridine(2.60 g, 6.91 mmol) was mixed with 30 mL of tetrahydrofuran, followed byaddition of 7.25 mmol of n-butyllithium at a temperature of −78° C. andstirring for 1 hour. Subsequently, tributyltin chloride (2.36 g, 7.25mmol) was added thereto, followed by stirring at room temperature for 3hours. After the completion of the reaction was confirmed, distilledwater was added thereto, and an organic layer was extracted therefromusing ethyl acetate. Next, anhydrous magnesium sulfate (MgSO₄) was addedthereto to remove water therefrom. Then, a filtration process wasperformed thereon to obtain a filtrate. From the filtrate, ethyl acetatewas removed under reduced pressure. As a result, Intermediate B6 wasobtained, which was used for the next reaction without being subjectedto additional purification.

Synthesis of Intermediate B5

Intermediate B6 (3.44 g, 5.87 mmol), 2-bromo-1,3-diiodobenzene (1.44 g,3.52 mmol), and Pd(PPh₃)₄ (0.34 g, 0.29 mmol) were added to 30 mL oftoluene (PhMe). The mixed solution was stirred at a temperature of 110°C. for 5 hours, and then, cooled to room temperature. Distilled waterwas added to the resulting mixture, and an organic layer was extractedtherefrom by using ethyl acetate, followed by addition of anhydrousMgSO₄ to dry the organic layer. Next, a filtration process was performedthereon to obtain a filtrate. Then, ethyl acetate in the obtainedfiltrate was removed under reduced pressure. The residue obtainedtherefrom was purified by column chromatography with ethylacetate:hexane=1:15 as an eluent to obtain 1.22 g (36%) of IntermediateB5. The obtained compound was confirmed by LCMS and ¹H NMR.

¹H-NMR (CDCl₃) δ 8.20 (d, 1H), 8.05 (d, 1H), 7.75 (m, 2H), 7.31 (m, 2H),6.88 (s, 1H), 5.89 (d, 1H), 4.01 (d, 1H), 3.52 (t, 1H), 2.53 (m, 1H),2.14 (m, 3H), 1.72 (m, 2H)

MS: m/z 577.97 [(M+1)⁺]

Synthesis of Intermediate B4

Intermediate B5 (1.22 g, 2.11 mmol), 2-bromophenylboronic acid (0.42 g,2.11 mmol), Pd(PPh₃)₄ ((0.17 g, 0.15 mmol), and K₂CO₃ (0.73 g, 5.28mmol) were mixed with 15 mL of THF and 5 mL of distilled water. Then,the mixture was stirred at a temperature of 75° C. for 4 hours, andthen, cooled to room temperature. An organic layer was extractedtherefrom by using ethyl acetate, followed by addition of anhydrousMgSO₄ to dry the organic layer. Next, a filtration process was performedthereon to obtain a filtrate. Then, ethyl acetate in the obtainedfiltrate was removed under reduced pressure. The residual was purifiedby column chromatography with ethyl acetate:hexane=1:15 as an eluent toobtain 1.06 g (83%) of Intermediate B4. The obtained compound wasconfirmed by LCMS and ¹H NMR.

¹H-NMR (CDCl₃) δ 8.16 (d, 1H), 8.05 (d, 1H), 7.68 (m, 4H), 7.55 (m, 2H),7.25 (m, 2H), 6.88 (s, 1H), 5.88 (d, 1H), 4.00 (d, 1H), 3.53 (t, 1H),2.52 (m, 1H), 2.11 (m, 3H), 1.69 (m, 2H)

MS: m/z 606.00 [(M+1)⁺]

Synthesis of Intermediate B3

At a temperature of −78° C., Intermediate B4 (1.06 g, 1.75 mmol) wasmixed with 18 mL of tetrahydrofuran. n-MeLi (3.50 mmol) in n-hexane wasslowly added dropwise thereto, and the reaction mixture was stirred at atemperature of −78° C. for 1 hour. Subsequently, PCl₃ (0.48 g, 1.75mmol) was added thereto, followed by stirring at room temperature for 1hour. After the completion of the reaction was confirmed, the reactionmixture was heated for 1 hour, and the resulting solution was cooled toroom temperature, thereby obtaining a 0.44 g (49%) of a solid product,Intermediate B3. The obtained compound was used for the next reactionwithout being subjected to additional purification.

MS: m/z 463.98 [(M+1)⁺]

Synthesis of Intermediate B2

At a temperature of 0° C., Intermediate B3 (0.44 g, 0.86 mmol) was mixedwith 10 mL of tetrahydrofuran. CH₃MgBr (0.86 mmol) was slowly addeddropwise thereto, and the reaction mixture was stirred at roomtemperature for 3 hours. After the completion of the reaction wasconfirmed, distilled water was added thereto, and an organic layer wasextracted therefrom by using ethyl acetate, followed by addition ofMgSO₄ to dry the organic layer. Next, a filtration process was performedthereon to obtain a filtrate. Then, ethyl acetate in the obtainedfiltrate was removed under reduced pressure. The residue obtainedtherefrom was purified by column chromatography with ethylacetate:hexane=1:25 as an eluent to obtain 0.42 g (85%) of IntermediateB2. The obtained compound was confirmed by LCMS and ¹H NMR.

¹H-NMR (CDCl₃) δ 8.26 (d, 1H), 8.03 (d, 1H), 7.80 (m, 3H), 7.55 (m, 4H),7.23 (d, 1H), 6.90 (s, 1H), 5.89 (d, 1H), 4.01 (d, 1H), 3.52 (t, 1H),2.51 (m, 1H), 2.13 (m, 3H), 2.01 (s, 3H), 1.70 (m, 2H)

MS: m/z 494.15 [(M+1)⁺]

Synthesis of Intermediate B1

Intermediate B2 (0.42 g, 0.73 mmol) was mixed with 10 mL of ethanol,followed by slow addition of PPTS (1.84 g, 7.30 mmol). The reactionmixture was then stirred at a temperature of 70° C. for 8 hours. Afterthe completion of the reaction was confirmed, distilled water was addedthereto, and an organic layer was extracted therefrom by using ethylacetate, followed by addition of MgSO₄ to dry the organic layer. Next, afiltration process was performed thereon to obtain a filtrate. Then,ethyl acetate in the obtained filtrate was removed under reducedpressure. The residue obtained therefrom was purified by columnchromatography with ethyl acetate:hexane=1:25 as an eluent to obtain0.27 g (91%) of Intermediate B1. The obtained compound was confirmed byLCMS and ¹H NMR.

¹H-NMR (CDCl₃) δ 11.9 (br. s, 1H), 8.25 (d, 1H), 8.02 (d, 1H), 7.81 (m,3H), 7.54 (m, 4H), 7.22 (d, 1H), 6.95 (s, 1H), 2.01 (s, 3H)

MS: m/z 410.09 [(M+1)⁺]

Synthesis of Compound 7

Intermediate B1 (0.27 g, 0.66 mmol) and OsH₄(PPh₃)₃ (0.28 g, 0.29 mmol)were mixed with 5 mL of decahydronaphthalene, and then the reactionmixture was reacted at a temperature of 200° C. for 2 hours.Subsequently, the mixture was cooled to room temperature. The residualobtained under reduced pressure was purified by column chromatographywith ethylacetate:hexane=1:10 as an eluent, thereby obtaining 64 mg(22%) of Compound 7. The obtained compound was confirmed by LCMS and ¹HNMR.

¹H-NMR (CDCl₃) δ 8.25 (d, 2H), 7.99 (d, 2H), 7.81 (m, 6H), 7.62 (m, 4H),7.50 (m, 2H), 7.38 (m, 4H), 6.97 (s, 2H), 2.00 (s, 6H)

MS: m/z 1009.12 [(M+1)⁺]

Example 1

A glass substrate, on which an anode having a structure of ITO/Ag/ITO(70 Å/1000 Å/70 Å) was deposited, was cut to a size of 50 millimeters(mm)×50 mm×0.5 mm, sonicated in isopropyl alcohol and water for 5minutes, respectively, and cleaned by exposure to ultraviolet rays for30 minutes, and then ozone. The glass substrate was mounted on avacuum-deposition device.

2-TNATA was deposited on the anode to form a hole injection layer havinga thickness of 600 Å. 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(hereinafter, referred as “NPB”) was deposited on the hole injectionlayer to form a hole transport layer having a thickness of 1,350 Å.

CBP (as a host) and Compound 1 (as a dopant) were co-deposited on thehole transport layer at a weight ratio of 94:6 to form an emission layerhaving a thickness of 400 Å. BCP was deposited on the emission layer toform a hole blocking layer having a thickness of 50 Å. Subsequently,Alq₃ was deposited on the hole blocking layer to form an electrontransport layer having a thickness of 350 Å. LiF was deposited on theelectron transport layer to form an electron injection layer having athickness of 10 Å. MgAg was deposited on the electron injection layer ata weight ratio of 90:10 to form a cathode having a thickness of 120 Å,thereby completing the manufacture of an organic light-emitting device(which emits red light).

Example 2 and Comparative Examples A and B

An organic light-emitting device (which emits red light) wasmanufactured in the same manner as in Example 1, except that in theformation of the emission layer, Compounds listed in Table 2 (wherein,in Compound B, “Ph” represents a phenyl group, and “Me” represents amethyl group) were used instead of Compound 1 as a dopant.

Evaluation Example 1: Evaluation of Characteristics of OrganicLight-Emitting Device

The driving voltage, luminescence efficiency, maximum emissionwavelength (λ_(max)), external quantum efficiency (EQE), full width athalf maximum (FWHM), and lifespan (LT₉₇) of the organic light-emittingdevices of Examples 1 and 2 and Comparative Examples A and B wereevaluated. The results thereof are shown in Table 2. A Keithley 2400current voltmeter and a luminance meter (Minolta Cs-1000A) were used inthe evaluation. The lifespan (T₉₇) (at 3,500 nit) refers to timerequired for the initial luminance of the organic light-emitting deviceto reduce by 97%.

TABLE 2 Driv- ing volt- Luminescence age efficiency λ_(max) EQE FWHMLT₉₇ Dopant (V) (cd/A) (nm) (%) (nm) (hr) Example 1 Com- 5.5 14.1 64321.3 55 230 pound 1 Example 2 Com- 4.4 27.5 609 23.0 59 350 pound 7Compara- Com- 6.4 18.3 550 5.2 93 45 tive pound Example A A Compara-Com- 4.9 18.5 620 17.1 98 35 tive pound Example B B

According to Table 2, it was found that the organic light-emittingdevices of Examples 1 and 2 employing Compounds 1 and 7 having a robusttridentate ligand, in which a chromophore moiety is linked to aphosphine-containing moiety via sp² type with a less vibrational mode,have the same or improved luminescence efficiency, excellent EQE,excellent lifespan, and smaller FWHM, as compared with the organiclight-emitting device of Comparative Example A having a tridentateligand, in which a chromophore moiety is linked to thephosphine-containing moiety via O in sp³ type.

In addition, according to Table 2, it was found that the organiclight-emitting devices of Examples 1 and 2 employing Compounds 1 and 7having a robust tridentate ligand have the same or improved luminescenceefficiency, excellent EQE, excellent lifespan, and smaller FWHM, ascompared with the organic light-emitting device of Comparative Example Bemploying Compound B having a monodentate phosphine-containing moietyand a bidentate chromophore moiety.

Without wishing to be bound by any particular theory, the improvement ofEQE and lifespan characteristics of the organic light-emitting devicesof Examples 1 and 2 may be resulted from the reduced non-emittingtransition caused by the reduced vibrational mode of Compounds 1 and 7due to the robust tridentate ligands of Compounds 1 and 7.

According to one or more embodiments, the organometallic compound hasexcellent electric characteristics and thermal stability, and thus, theorganic light-emitting device including the organometallic compound mayhave excellent driving voltage, efficiency, electric power, colorpurity, and lifespan characteristics. In addition, the organometalliccompound has excellent phosphorescent emission characteristics. In thisregard, when the organometallic compound used for a diagnosticcomposition, the diagnostic composition may have a high diagnosticefficiency.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present disclosure as definedby the following claims.

What is claimed is:
 1. An organometallic compound represented by Formula1:

wherein, in Formulae 1 and 2, M is a third row transition metal, L₁₁ isa ligand represented by Formula 2, n1 is 1 or 2, and when n1 is two, twogroups L₁₁ are identical to or different from each other, L₁₂ is anorganic ligand, n2 is 0, 1, 2, or 3, and when n2 is two or more, two ormore of groups L₁₂ are identical to or different from each other, X₁ isB(R₇), N(R₇), P(R₇), or As(R₇), X₂ and X₃ are each N or C, CY₁ to CY₄are each independently selected from a C₅-C₃₀ carbocyclic group and aC₁-C₃₀ heterocyclic group, provided that when X₁ is N(R₇), X₂ is N, andX₃ is N, then CY₄ is not pyridine, T₁ and T₂ are each independentlyselected from a single bond, a double bond, *—N[(L)_(b5)-(R₅)_(c5)]—*′,*—B(R₅)—*′, *—P(R₅)—*′, *—C(R₅)(R₆)—*′, *—Si(R₅)(R₆)—*′,*—Ge(R₅)(R₆)—*′, *—S—*′, *—Se—*′, *—O—*′, *—C(═O)—*′, *—S(═O)—*′,*—S(═O)₂—*′, *—C(R₅)=*′, *═C(R₅)—*′, *—C(R₅)═C(R₆)—*′, *—C(═S)—*′, and*—C≡C—*′, L₁ to L₅ are each independently selected from a single bond, asubstituted or unsubstituted C₅-C₃₀ carbocyclic group, and a substitutedor unsubstituted C₁-C₃₀ heterocyclic group, b1 to b5 are eachindependently an integer of 1 to 5, R₅ and R₆ are optionally linked viaa single bond or a first linking group to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, R₁ to R₇ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₇-C₆₀ arylalkyl group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryloxy group, a substituted or unsubstituted C₁-C₆₀heteroarylthio group, a substituted or unsubstituted C₂-C₆₀heteroarylalkyl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, a substituted or unsubstitutedmonovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂),—Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q)(Q₉), c1 to c5 are eachindependently an integer of 1 to 5, a1 to a4 are each independently aninteger of 0 to 20, two of a plurality of neighboring groups R₁ areoptionally linked to form a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, two of a plurality of neighboring groups R₂ are optionally linkedto form a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃ heterocyclic group, two of aplurality of neighboring groups R₃ are optionally linked to form asubstituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃ heterocyclic group, two of a plurality ofneighboring groups R₄ are optionally linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, two or more of neighboring R₁ to R₄ areoptionally linked to form a substituted or unsubstituted C₅-C₃₀carbocyclic group or a substituted or unsubstituted C₁-C₃₀ heterocyclicgroup, *, *′, and *″ in Formula 2 each independently indicate a bindingsite to M of Formula 1, at least one substituent of the substitutedC₅-C₃₀ carbocyclic group, the substituted C₁-C₃₀ heterocyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₇-C₆₀ arylalkyl group, the substitutedC₁-C₆₀ heteroaryl group, the substituted C₁-C₆₀ heteroaryloxy group, thesubstituted C₁-C₆₀ heteroarylthio group, the substituted C₂-C₆₀heteroarylalkyl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I,—CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀ alkoxy group, each substitute with at leastone selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,—CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃—C cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ aryloxy group, aC₁-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroarylgroup, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, aC₂-C₆₀ heteroarylalkyl group, a monovalent non-aromatic condensedpolycyclic group, a monovalent non-aromatic condensed heteropolycyclicgroup, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and—P(═O)(Q₁₈)(Q₁₉); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀heteroarylalkyl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group; aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, aC₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂),—Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),and Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ are eachindependently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl groupsubstituted with at least one selected from deuterium, a C₁-C₆₀ alkylgroup, and a C₆-C₆₀ aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with at least one selected from deuterium, a C₁-C₆₀ alkylgroup, and a C₁-C₆₀ aryl group, a C₁-C₆₀ aryloxy group, a C₆-C₆₀arylthio group, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroaryl group, aC₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀heteroarylalkyl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group.2. The organometallic compound of claim 1, wherein M is Os and n1 is 1or 2; or M is Pt, n1 and n2 are each 1, and L₁₂ is a monodentate organicligand.
 3. The organometallic compound of claim 1, wherein X₁ is P(R₇).4. The organometallic compound of claim 1, wherein X₂ is N and X₃ is C;X₂ is C and X₃ is N; or X₂ and X₃ are each N.
 5. The organometalliccompound of claim 1, wherein CY₁ to CY₄ are each independently selectedfrom a benzene group, a naphthalene group, an anthracene group, aphenanthrene group, a triphenylene group, a pyrene group, a chrysenegroup, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, apyrrole group, a thiophene group, a furan group, an indole group, anisoindole group, a benzoborole group, a benzophosphole group, an indenegroup, a benzosilole group, a benzogermole group, a benzothiophenegroup, a benzoselenophene group, a benzofuran group, a carbazole group,a dibenzoborole group, a dibenzophosphole group, a fluorene group, adibenzosilole group, a dibenzogermole group, a dibenzothiophene group, adibenzoselenophene group, a dibenzofuran group, a dibenzothiophene5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxidegroup, an azacarbazole group, an azadibenzoborole group, anazadibenzophosphole group, an azafluorene group, an azadibenzosilolegroup, an azadibenzogermole group, an azadibenzothiophene group, anazadibenzoselenophene group, an azadibenzofuran group, anazadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, anazadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidinegroup, a pyrazine group, a pyridazine group, a triazine group, aquinoline group, an isoquinoline group, a quinoxaline group, aquinazoline group, a phenanthroline group, a pyrazole group, animidazole group, a triazole group, a tetrazole group, an oxazole group,an isooxazole group, a thiazole group, an isothiazole group, anoxadiazole group, a thiadiazole group, a benzopyrazole group, abenzimidazole group, a benzoxazole group, a benzothiazole group, abenzooxadiazole group, a benzothiadiazole group, a5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinolinegroup.
 6. The organometallic compound of claim 1, wherein T₁ and T₂ areeach a single bond.
 7. The organometallic compound of claim 1, whereinR₁ to R₇ are each independently selected from: hydrogen, deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, —SF₅, a C₁-C₂₀ alkylgroup, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₁-C₁₀ alkyl group, a cyclopentyl group,a cyclohexyl group, a cycloheptyl group, a cycloctyl group, anadamantanyl group, a norbornanyl group, a norbornenyl group, acyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, aphenyl group, a naphthyl group, a pyridinyl group, and a pyrimidinylgroup; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acycloctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, an imidazopyridinyl group, and an imidazopyrimidinyl group; acyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cycloctylgroup, an adamantanyl group, a norbornanyl group, a norbornenyl group, acyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, aphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenylgroup, an anthracenyl group, a fluoranthenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, an imidazolyl group, a pyrazolylgroup, a thiazolyl group, an isothiazolyl group, an oxazolyl group, anisoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, an indolyl group, anindazolyl group, a purinyl group, a quinolinyl group, an isoquinolinylgroup, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinylgroup, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group,a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group,an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolylgroup, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, atriazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, and an imidazopyrimidinyl group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,—CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cycloctyl group, an adamantanyl group, anorbornanyl group, a norbornenyl group, a cyclopentenyl group, acyclohexenyl group, a cycloheptenyl group, a phenyl group, a naphthylgroup, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a pyrrolyl group, a thiophenyl group, a furanyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a pyridinyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolylgroup, an indolyl group, an indazolyl group, a purinyl group, aquinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group; and —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇),and —P(═O)(Q)(Q₉); Q₁ to Q₉ are each independently be selected from:—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃,—CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CH₃, —CD₂CD₂H, and —CD₂CDH₂;an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group; and an n-propyl group, an iso-propyl group,an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butylgroup, an n-pentyl group, an isopentyl group, a sec-pentyl group, atert-pentyl group, a phenyl group, and a naphthyl group, eachsubstituted with at least one selected from deuterium, a C₁-C₁₀ alkylgroup, and a phenyl group.
 8. The organometallic compound of claim 1,wherein R₁ to R₇ are each independently selected from hydrogen,deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H,—CDH₂, —CF₃, —CF₂H, —CFH₂, groups represented by Formulae 9-1 to 9-19,groups represented by Formulae 10-1 to 10-139, —N(Q)(Q₂),—Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), wherein Q₁ to Q₉ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryl group substituted with at least one selected from a C₁-C₆₀ alkylgroup and a C₁-C₆₀ aryl group, a C₁-C₆₀ aryloxy group, a C₁-C₆₀ arylthiogroup, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀heteroarylalkyl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group:

wherein, in Formulae 9-1 to 9-19 and 10-1 to 10-139, “Ph” indicates aphenyl group, “TMS” indicates a trimethylsilyl group, and “*” indicatesa binding site to a neighboring atom.
 9. The organometallic compound ofclaim 1, wherein a moiety represented by

in Formula 2 is represented by one selected from Formulae CY1-1 toCY1-12:

wherein, in Formulae CY1-1 to CY1-12, X₁, R₁, and R₂ are eachindependently the same as described in claim 1, a14 is an integer of 0to 4, a13 and a23 are each an integer of 0 to 3, a12 and a22 are each aninteger of 0 to 2, * indicates a binding site to M of Formula 1, and *′″indicates a binding site to a neighboring atom.
 10. The organometalliccompound of claim 1, wherein a moiety represented by

in Formula 2 is represented by one selected from Formulae CY3-1 toCY3-9:

wherein, in Formulae CY3-1 to CY3-9, X₂ and R₃ are each the same asdescribed in claim 1, a35 is an integer of 0 to 5, a34 is an integer of0 to 4, a33 is an integer of 0 to 3, a32 is an integer of 0 to 2, *′indicates a binding site to M of Formula 1, *′″ and

each indicate a binding site to a neighboring atom.
 11. Theorganometallic compound of claim 1, wherein a moiety represented by

in Formula 2 is represented by one selected from Formulae CY4-1 toCY4-40:

wherein, in Formulae CY4-1 to CY4-40, X₃ and R₄ are each the same asdescribed in claim 1, X₄₁ is O, S, N(R₄₁), or C(R₄₁)(R₄₂), R₄₁ to R₄₈are each the same as described in connection with R₄ in claim 1, a46 isan integer of 0 to 6, a45 is an integer of 0 to 5, a44 is an integer of0 to 4, a43 is an integer of 0 to 3, a42 is an integer of 0 to 2, *″indicates a binding site to M of Formula 1, and

indicates a binding site to a neighboring atom.
 12. The organometalliccompound of claim 1, wherein a moiety represented by

in Formula 2 is represented by Formula CY1(1), a moiety represented by

in Formula 2 is represented by one selected from Formula CY3(1) toCY3(11), and a moiety represented by

in Formula 2 is represented by one selected from Formulae CY4(1) toCY4(23):

wherein, in Formulae CY1(1), CY3(1) to CY3(11), and CY4(1) to CY4(23),X₁ to X₃, R₃, and R₄ are each the same as described in claim 1, X₄₁ isO, S, N(R₄₁), or C(R₄₁)(R₄₂), R_(4a) to R_(4d), R₄₁, and R₄₂ are eachindependently the same as described in connection with R₄, providedthat, R₃, R₄, R_(4a) to R_(4a), R₄₁, and R₄₂ are not each independentlyhydrogen, *, *′, and *″ each independently indicate a binding site to Mof Formula 1, and *′″ and

each indicate a binding site to a neighboring atom.
 13. Theorganometallic compound of claim 1, wherein L₁₂ in Formula 1 is selectedfrom ligands represented by Formulae 3A to 3D and 6-1:

wherein, in Formulae 3A to 3D, Y₁₁ is selected from O, N, N(Z1),P(Z₁)(Z₂), and As(Z₁)(Z₂), Y₁₂ is selected from O, N, N(Z₃), P(Z₃)(Z₄),and As(Z₃)(Z₄), T₁₁ is selected from a single bond, a double bond,*—C(Z₁₁)(Z₁₂)—*′, *—C(Z₁₁)═C(Z₁₂)—*′, *═C(Z₁₁)—*′, *—C(Z₁₁)=*′,*═C(Z)—C(Z₁₂)═C(Z₃)—*′, *—C(Z₁₁)═C(Z₁₂)—C(Z₁₃)=*′, *—N(Z₁₁)—*′, and asubstituted or unsubstituted C₆-C₃₀ arylene group, a11 is an integer of1 to 5, Y₁₃ to Y₁₆ are each independently be C or N, a bond between Y₁₃and Y₁₄ is single bond or a double bond, and a bond between Y₁₅ and Y₁₆is a single bond or a double bond, CY₁₁ to CY₁₃ are each independentlyselected from a C₅-C₃₀ carbocyclic group and a C₂-C₃₀ heterocyclicgroup, Z₁ to Z₄ and Z₁₁ to Z₁₃ are each independently the same asdescribed in connection with R₁ in claim 1, d1 and d2 are eachindependently an integer of 0 to 10, * and *′ each indicate a bindingsite to M of Formula 1, in Formula 6-1, T₃ is selected from a singlebond, *—O—*′, *—S—*′, *—C(R₆₂)(R₆₃)—*′, *—C(R₆₂)=*′, *═C(R₆₂)—*′,*—C(R₆₂)═C(R₆₃)—*′, *—C(═O)—*′, *—C(═S)—*′, *—C≡C—*′, and *—N(R₆₂)—*, t3is an integer of 1 to 5, R₆₁ to R₆₃ are each independently the same asdescribed in connection with R₁ in claim 1, or are each independently—P(Q₄₁)(Q₄₂)(Q₄₃), Q₄₁ to Q₄₃ are each independently the same asdescribed in connection with R₁ in claim 1, and * indicates a bindingsite to M of Formula
 1. 14. The organometallic compound of claim 1,wherein L₁₂ in Formula 1 is selected from ligands represented byFormulae 13-1 to 13-47 and 14-1 to 14-28:

wherein, in Formulae 13-1 to 13-47 and 14-1 to 14-28, R₆₁ to R₆₃, Q₄₁ toQ₄₃, and Z₁ to Z₃ are each independently the same as described inconnection with R₁ in claim 1, d2 is an integer of 0 to 2, d3 is aninteger of 0 to 3, d4 is an integer of 0 to 4, d5 is an integer of 0 to5, d6 is an integer of 0 to 6, d7 is an integer of 0 to 7, d8 is aninteger of 0 to 8, and * indicates a binding site to M of Formula
 1. 15.The organometallic compound of claim 1, wherein the organometalliccompound is one selected from Compounds 1 to 46:

wherein, in Compounds 1 to 46, “^(t)Bu” indicates a tert-butyl group.16. An organic light-emitting device, comprising: a first electrode, asecond electrode, and an organic layer disposed between the firstelectrode and the second electrode, wherein the organic layer comprisesan emission layer and at least one organometallic compound of claim 1.17. The organic light-emitting device of claim 16, wherein the firstelectrode is an anode, the second electrode is a cathode, and theorganic layer further comprises a hole transport region disposed betweenthe first electrode and the emission layer and an electron transportregion disposed between the emission layer and the second electrode,wherein the hole transport region comprises a hole injection layer, ahole transport layer, an electron blocking layer, or any combinationthereof, and wherein the electron transport region comprises a holeblocking layer, an electron transport layer, an electron injectionlayer, or any combination thereof.
 18. The organic light-emitting deviceof claim 16, wherein the emission layer comprises the organometalliccompound.
 19. The organic light-emitting device of claim 18, wherein theemission layer further comprises a host, and wherein an amount of thehost is greater than that of the organometallic compound.
 20. Adiagnostic composition comprising at least one of the organometalliccompound of claim 1.